Fractures and Bone Disease in Living Kidney Donors

Inclusion Criteria: Aim 1: Survey (Donors): * Donated a kidney at one of the three participating sites. * 10 or more years have passed since donation. * Age ≥ 50 at time of study enrollment. Aim 1: Survey (Controls): * Subjects in the REP population. * Medical records available for the five years preceding age at matching (age at donation). * Matching will be based on: age, year of donation, sex, race/ethnicity, body mass index, comorbidity and selected risk factors (smoking, education level) status at year of donation Aim 2: Skeletal health assessment (Donors and Controls): * Subjects who have completed the survey * Willing to come in for the in-person assessment Exclusion Criteria: Aim 1: Survey (Donors): * Deceased * Not willing to return the survey. Aim 1: Survey (Controls): * Deceased * Not willing to return the survey * History of the following conditions: * Diabetes mellitus, liver disease, kidney disease, nephrolithiasis, malabsorption syndrome, past history of non-traumatic fractures. Aim 2: Skeletal health assessment (Donors and Controls): * Subjects who did not participate in the survey * Subjects not willing to come for the in-person evaluation. * Women of childbearing potential.